Aryl arsine oxides



. the hitherto known arsine oxides.

tolera-ta per 20 grams of the weight of a mouse Patented May 20, 1941UNITED STATES PATENT OFF-ICE ARYL ARSINE OXIDES Walter Herrmann andFriedrich Hampe, Frankfort-on-the-Main-Hochst, Germany, assignors toWinthrop Chemical Company, Inc, New York, N. Y., a corporation of NewYork a I No Drawing. Application April 26, 1939, Serial No. 270,156.. InGermany April 29, 1938 2 Claims.

-The present invention relates to new aryl arsine oxides and to aprocess .of preparing them.

Aryl arsine oxides have already been included for a long time past intothe sphere of chemotherapeutic investigations. In recent times it hasalso been proposed to use the 3-amino-4-hydroxybenzene arsine oxide,known for a long time, for curing protozoa-diseases.

We have found that the 2-mercaptobenzimidazole-4-arsine oxide of theformula and the 2-mercaptobenzimidazole-5-arsine oxide of the formulahave a surprisingly high activity exceeding all The dosis injectedintravenously is, for instance, for Z-mercaptobenzimidazole-S-arsineoxide and for 3- amino-4-hydroxybenzene arsine' oxide (which is knowntobe especially active) 0.2 milligram. The dosis curativa in the case oftrypanosoma (the stock Provatschek) is 0.005 milligram for 2-merca'ptobenzimidazole-5-arsine oxide whereas 0.02 milligram of3-amino-4-hydroxybenzene arinvention, but it is not intended to limit itthereton 27.4 grams of 2-mercaptobenzimidazole-5- arsonic acid aredissolved in 130 cc. of water with addition of 7.5 cc. of caustic sodasolution of 42 B. A solution of 10' grams of potassium iodide in 20 cc.of water and then 260 cc. of sulfuric acid (1 to 5) are added to thissolution. Sul-- furous acid is then introduced without regard to anyprecipitation which may occur, until satura tion has occurred. The wholeis-then filtered and washed with a large quantity of water and theprecipitate is dried. The 2-mercaptobenzimida zble-S-arsine oxide is a,white powder readily soluble in acids and alkalis.

The corresponding 2-mercaptobenzimidazole-iarsine oxide is obtained inthe same manner by starting from 2-mercaptobenzimidazole-l-arsonic acid.

We claim:

1. A spirocheticidal and trypanosomicidal composition prepared fortherapeutic use in a form of sufiicient purity, comprising a compound ofthe class consisting of the two compounds of the following formula:

wherein the arsenic containing radical stands in a position of the groupconsisting of the 4- and 5-positions.

2. A spirocheticidal and trypanosomicidal composition prepared fortherapeutic use in a form of sufficient purity comprising a compound ofthe following formula: III

v osn WALTER HERRMAN N FRIEDRICH HAMPE.

